The present invention relates to a combined kiln and lid prop and more particularly to such a combination in which a lid prop is pivotally mounted on the side of an upright kiln having an upwardly opening lid for pivotal movement between an upright position with the lid pivotally rested thereon and an outwardly and downwardly pivoted position, the prop having a center of gravity outward of its pivotal mounting so that when the lid is lifted from the prop the latter automatically pivots away from the lid allowing closure thereof. In a second form of the invention, the lid has a manipulating handle having an opening therein and the prop has an extended portion releasably fitted to the handle opening when in propping position.
There are many varieties of kiln structures used in firing ceramic materials having a wide range of sizes. The type of kiln involved in the present invention is that employed in the home, laboratory or other location to fire ceramic ware of artistic and/or functional nature which is small enough and light enough for manual formation and positioning. The kiln is typified by those used by hobbiests.
In the making of ceramic articles, a suitable clay or other ceramic raw material is first mixed with sufficient water to give it plasticity. This normally requires the material to contain from 15 to 25 percent water by weight.
The plastic raw material is then formed by hand molding, jiggering, extrusion, pressing, or casting. Once this is accomplished, the formed object has its excess water removed in a dryer or kiln. In fact, whether pre-dried in a dryer or sent directly to a kiln, it is the normal practice when the object reaches the kiln to leave the kiln open for several hours to permit ventilation and evaporation of excessive moisture. The kiln is normally heated during such period to facilitate evaporation although care is exercised to avoid cracking due to a too rapid rate of drying.
Conventionally, the kiln is held open by placing a brick or other obstruction under the lid of the kiln, which brick is removed when the drying cycle is completed. Unfortunately, kilns are normally lined with a soft pumice insulation. The engagement of bricks with such insulation wears away the insulation and the bricks causing premature deterioration of the kilns and particles from the worn insulation and the bricks enter the kilns damaging the soft objects being dried therein. Further, this primitive but customary procedure requires an attendant to use both hands in propping or unpropping kiln lids.
It has long been recognized that the provision of improved means for propping open the lids of kilns which do not subject the objects undergoing firing to contamination nor impair the kiln insulation would be of considerable practical advantage.